@rbxts/jsnatives

warn

Outputs a warning message to the console with distinctive formatting to indicate a potential issue.

Signature

function warn(...args: unknown[]): void

Description

The console.warn method prints one or more values to the console, typically with yellow text or warning styling. Like console.warn, it supports string formatting when the first argument is a string, and automatically inspects objects.

Parameters

...args: A list of values to output to the console as a warning. If the first argument is a string, it can contain format specifiers.

Return value

None (void).

Examples

Basic usage

// Logging a simple string
console.warn("Hello world");
// Outputs: Hello world (with indentation)

// Logging with string formatting
console.warn("Player %s has score %d", "Alex", 42);
// Outputs: Player Alex has score 42 (formatted string with indentation)

// Logging numbers without formatting
console.warn(42);
// Outputs: 42 (with indentation)

String formatting

// Using string format specifiers (like Lua's string.format)
console.warn("Pi is approximately %.2f", 3.14159);
// Outputs: Pi is approximately 3.14

// Multiple arguments
console.warn("Player: %s, Level: %d, Active: %s", "John", 5, true);
// Outputs: Player: John, Level: 5, Active: true

// Percent sign
console.warn("Progress: %d%%", 75);
// Outputs: Progress: 75%

Logging objects

// Logging an object (uses inspection)
const player = {
  name: "PlayerOne",
  level: 5,
  health: 100,
  inventory: ["sword", "shield", "potion"]
};

console.warn(player);
// Outputs an inspected representation without indentation:
// {name: "PlayerOne", level: 5, health: 100, inventory: ["sword", "shield", "potion"]}

Logging arrays

// Logging an array
const items = ["apple", "banana", "orange"];
console.warn(items);
// Outputs inspected array without indentation:
// ["apple", "banana", "orange"]